export default {
  namespaced:true,
  
  state: () =>   ({
    //购物车的数组，用来存储购物车中每个商品的信息对象
    // 每个商品的信息对象，都包含如下 6 个属性：
    // {goods_id, goods_name, goods_price, goods_count, goods_small_logo, goods_state}
    cart:JSON.parse(uni.getStorageSync('cart') || '[]')
  }),
  
  
  mutations: {
    addToCart(state,  goods){
    const findResult =  state.cart.find(x => x.goods_id === goods.goods_id)
    // console.log(findResult)
    
    if(!findResult){
      state.cart.push(goods)
    } else{
      findResult.goods_count++
    }    
    // console.log(state.cart)    
    this.commit('m_cart/saveToStorage')
    },
    saveToStorage(state){
      uni.setStorageSync('cart', JSON.stringify(state.cart))
    },
    updateGoodsState(state,goods){
    const findResult =  state.cart.find(x => x.goods_id === goods.goods_id)
    
    if(findResult){
      findResult.goods_state = goods.goods_state
      this.commit('m_cart/saveToStorage')
    }
    },
    updateGoodsCount(state,goods){
     const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
     if(findResult){
       findResult.goods_count = goods.goods_count
       
       this.commit('m_cart/saveToStorage')
     }
    },
    removeGoodsById(state, goods_id){
     state.cart = state.cart.filter(x => x.goods_id !== goods_id)
     
     this.commit('m_cart/saveToStorage')
    },
    updateAllGoodsState(state ,newState){
      state.cart.forEach(x  => x.goods_state = newState)
      
      this.commit('m_cart/saveToStorage')
    }
    
  },
  
  getters: {
    //购物车中所有商品的总数量
    total(state){
      // let c = 0
      // state.cart.forEach( x => c += x.goods_count)
      // return c 
    return  state.cart.reduce( (total,item) => total += item.goods_count ,0)
    },
    //购物车中已经勾选的商品数量
    checkedCount(state){
     return state.cart.filter(x =>  x.goods_state).reduce((total, item) =>   total += item.goods_count, 0)
    },
    checkedGoodsAmount(state){
    return  state.cart.filter( x => x.goods_state).reduce( (total,item) => total +=item.goods_count * item.goods_price ,0).toFixed(2)
    }
  }
}